Importance of philosophy, philosophy and religion, philosophy and science, philsosophy and ethics
Deductive and Inductive reasoning (wrt JS Mill & Aristotle)
Plato
Aristotle
Descartes
Locke
Hegel
Marx
Pragmaticism-William James
Logical positivism
Existentialism
Ibn e Sina
Al-ghazali
Ibn e Khildun
Iqbal

(You may still skip Muslim Philosophers)
Good luck